The invention relates generally to self-adjusting magnetic guidance devices and more particularly to a self-adjusting magnetic guidance device for stabilizing the trajectory of a vehicle suspended in a magnetic field.
The difficulties involved in developing non-contact devices to stabilize the trajectory of a vehicle suspended in a magnetic field became apparent in the 1960s, when high-speed ground transportation systems utilizing magnetic suspension were initially planned.
Several solutions to this problem have been proposed. At the present time, the following approaches are under development or being tested:
1. Electromagnets positioned on the vehicle are attracted to steel rails (i.e., strips) extending along both sides of the entire vehicle guideway.
2. Electromagnets or permanent magnets disposed on the vehicle are repelled by non-magnetic metal strips extending along both sides of the guideway.
Known devices utilizing the first approach require the following components on-board the vehicle itself: a) a highly-responsive regulating system that maintains precise control of the width of the air gaps between the poles of the electromagnets and the steel rails; and b) a powerful source of electric current. Any irregularity in either the regulating system or the power supply could lead to a serious accident.
A device utilizing the second approach is self-regulating and therefore more reliable than the first approach. A stabilizing force is created which increases in strength when there is an increase in the degree of deflection of the vehicle from the trajectory assigned it by the metal conducting strips. As the magnets move along the conducting strips, eddy currents are induced in the strips, creating electromagnetic forces which repulse and brake. For this reason the operation of the stabilizing device requires the expenditure of some of the power from the propulsion motor. This fraction of the power used to overcome electromagnetic braking is equal to the motor power losses dissipated in the form of heat in the conducting strips.
In view of the prior art, there is a need for a self-adjusting magnetic guidance device that overcomes the above-mentioned problems.